design LP,HP,B S digital Butterworth and Chebyshev
filter. All array has been specified internally,so user only need to
input f1,f2,f3,f4,fs(in hz), alpha1,alpha2(in db) and iband (to specify
the type of to design). This program output hk(z)=bk(z)/AK(z),k=1,2,...,
ksection and the freq.
he basic idea of the method of bisection is to start with an initial interval, [a0,b0], that is chosen so that f(a0)f(b0) < 0. (This guarantees that there is at least one root of the function f(x) within the initial interval.) We then iteratively bisect the interval, generating a sequence of intervals [AK,bk] that is guaranteed to converge to a solution to f(x) = 0.